Eruption Interval Monitoring at Strokkur Geyser, Iceland

Eva P S Eibl,Gylfi Páll Hersir,Nele I K Vesely,Torsten Dahm,Sebastian Hainzl,Thomas R Walter,Philippe Jousset

doi:10.1029/2019gl085266

Abstract

AbstractGeysers are hot springs whose frequency of water eruptions remain poorly understood. We set up a local broadband seismic network for 1 year at Strokkur geyser, Iceland, and developed an unprecedented catalog of 73,466 eruptions. We detected 50,135 single eruptions but find that the geyser is also characterized by sets of up to six eruptions in quick succession. The number of single to sextuple eruptions exponentially decreased, while the mean waiting time after an eruption linearly increased (3.7 to 16.4 min). While secondary eruptions within double to sextuple eruptions have a smaller mean seismic amplitude, the amplitude of the first eruption is comparable for all eruption types. We statistically model the eruption frequency assuming discharges proportional to the eruption multiplicity and a constant probability for subsequent events within a multituple eruption. The waiting time after an eruption is predictable but not the type or amplitude of the next one.

Highlights

A geyser is a multiphase geothermal feature that exhibits frequent, jetting eruptions of hot water and noncondensable gases such as CO2
Triple, quadruple, quintuple, or sextuple eruptions, tafter is on average 6.2±1.3 min, 8.8±2.0 min, 11.3±2.9 min, 14.1±2.4 min, and 16.4 min, respectively (Figures 2e–2i)
This is repeated until y > p and the eruption multiplicity n is given. (iii) The discharge due to the eruption is sampled from a log-normal distribution, that is, Δx = n exp(y) with y randomly selected from a normal distribution with zero mean and standard deviation σ. (iv) The state variable is reset to x(t) = xc − Δx, and the rupture time is determined by step (i)

Summary

Introduction

A geyser is a multiphase geothermal feature that exhibits frequent, jetting eruptions of hot water and noncondensable gases such as CO2. It is composed of a conduit, a reservoir with water supply, and a heat source (Descloizeaux, 1847; Munby, 1902). With respect to the eruption processes, which involves bubble formation and expansion, geysers have been considered as volcano analogs (Kieffer, 1984). The study of the dynamics and interdependencies of geyser eruptions may improve the understanding of how volcanoes work (Kieffer, 1984; Hurwitz & Manga, 2017)

Results

Discussion

Conclusion